How are nasal plates in dogs, ox and pigs are kept moist?

Ox, pig: underlying glandsDog: overflow from nasal cavity

The external nose has a nasal plate in ______, a nasolabial plate in _______ and a rostral plate in ________.

Carnivores and small ruminantsOxPig

22

What is the nasal vestibule? How does it differ in horses?

A narrow passage from the nostril to the wider nasal cavity. The mucocutaneous junction within the vestibule is the site of opening of lateral nasal gland ducts (and the nasolacrimal duct in the horse).

In the horse, the vestibule is divided into a ventral (true nostril) and dorsal part (nasal diverticulum).

23

Nasal cavity: What separates it from the oral cavity?What limits it caudally?It is divided into small passages by...?How does it communicate with nasopharynx?

Hard palateEthmoid boneConchae (turbinate bones)Choanae

24

What is the alar cartilage?

Cartilage on lateral wing of nostril

25

The nasal conchae are also called nasal turbinate bones. There are three including...? Their main function is what?

Function is to increase SA for heat exchange, filtration, humidification and olfaction

26

The lateral nasal gland is only present in _____ and opens in the ?lateral/medial? Wall of nasal vestibule. The nasolacrimal duct has a distal opening in the nasal vestibule at the _______ in the 🐴 and _________ in the 🐶

The larynx in birds is not used for vocalisation. It occupies the (1)___________ on the floor of the pharynx and is supported by the cricoid and (2)__________ cartilages (but no (3)_______). The bird also has no vocal folds.

1. Laryngeal mound2. Arytenoid3. Epiglottis

44

The trachea bifurcated at the level of which vertebrae?

Its cartilage rings are composed of what type of cartilage?

4-5th thoracic vertebraeHyaline

45

What is the smooth involuntary muscle forming the roof of the trachea? How does this differ among species?

What is the carina?

Trachealis muscle. Attaches on the lumen surface in horses and ox but on the outer surface in dogs.

Carina is the cartilaginous ridge at the tracheal bifurcation

46

What is the sequence of airway branching from the trachea?What is a bronchopulmonary segment and a pulmonary acinar?

Embryonic foregutLaryngotracheal grooveDay 17

What are some examples of congenital defects that may occur during airway development?

2. Tracheal hypoplasia (abnormal narrowing of trachea due to defect in growth of cartilages)

3. Accessory lungs

49

How does the trachea differ in birds? What side of the neck is it palpable on? Where does it bifurcate?

It has complete overlapping cartilaginous rings. Palpable on the right side. Bifurcated dorsal to the base of the heart

50

What is the syrinx? Where is it located? What is the pessulus?

Vocal organ of the bird located at the bifurcation of the trachea. The bronchial openings of the syrinx are separated by vertical wedge-shaped cartilage called the pessulus.

51

Describe the bronchi in birds 🐦(4 main points)

🔹2 principal bronchi🔹Secondary bronchi (40-50) branch off through the lung at regular intervals🔹About 400-500 tertiary bronchi called parabronchi arise from each secondary bronchus. They anastomose with each other.🔹Loops from walls of parabronchi through lung tissue and back to parabronchi form air capillaries

52

Avian air sacs are connected by secondary bronchi to the lungs and principal bronchi. They are the space for expansion of respiratory tract. Describe their divisions.

Expiratory:-normally passive-forced expiration is by internal intercostals and abdominal muscles

What are the steps involved in inspiration and expiration?

Inspiration:Contraction of diaphragm-->expansion of thorax--> drop in pressure in pleural cavity (754mm Hg)-->lung expansion and drop in intra-alveolar pressure--> airflow down pressure gradient into lungs

Expiration:Relaxation of inspiratory muscles--> decrease in thoracic and lung volume-->increased intra-alveolar pressure--> airflow down pressure gradient out of lungs

63

What is atelectasis?

Airflow into thorax resulting in loss of partial vacuum and lung collapse

64

Where does the cardiac notch occur?

At about the 3rd-5th intercostal space

65

The apex of the lungs lies adjacent to...? What composes the root of the lung?

What is the formula for the rate of gas diffusion through tissues?

DR= (PD x A x DC) / T

What happens if your diffusion reserve is exhausted?

Hypoxaemia without hypocapnia

78

How much O2 is carried via Hb in the blood?

98.5%

79

Explain the oxygen-haemoglobin saturation curve.

It illustrates the percentage of Hb bound to oxygen at different blood PO2 pressures. It is a sigmoid curve because the affinity of a particular heme group for oxygen is influenced by oxygenation of other heme groups.

80

What is the Bohr effect/shift?

A right shift ( and hence decreased oxygen affinity)in the oxygen-Hb saturation curve due to an increase in CO2 tension

81

What is the Haldane effect?

The increased affinity of reduced Hb for CO2

82

What are the two reactions CO2 can undergo in the erythrocyte?

1. Join with H2O to form H2CO3 and then HCO3- and H+.2. Join with Hb to form carbaminohaemoglobin and H+

83

Briefly explain the difference between respiratory acidosis and alkalosis.

Resp. acidosis: increased PCO2 in the bloodResp. alkalosis: decreased PCO2 in the blood

84

If there is a metabolic acidosis/alkalosis, would we expect pH and [HCO3-] to move in the same or opposite direction?

Same direction. They would move in the opposite direction if change was respiratory in origin

85

There are 5 aggregations of neuronal cell bodies involved in the control of ventilation. Name them and identify where they can be found.